The current version of R is R-2.0.0. The development cycle of R is very rapid, and almost every six months (April and October), new versions of R are out. In between, alpha and beta versions are put on the websites for testing. The source codes and binary versions of R can be downloaded from http://cran.r-project.org. It has many mirrors. In addition to downloading R directly from the website, it can also be obtained on a CD in many linux distributions, and you can also write to me for obtaining R.